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B. W. GILLON.

v METHOD OF TEMPERING BESSEMER STEEL WIRE.

No. 379,573. Patented Mar. 20, 1888.

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jaa mvz at 6125071 UNITED v STATES PATENT OFFICE.

EDWARD WV. GILLON, OF BROOKLYN, NEW YORK.

METHOD OF TEMPERING BESSEMER-STEEL WIRE.

SPECIFICATION forming part of Letters Patent No. 379,573, dated March 20, 1888.

(No model.)

.To all whom it; may concern.-

Be it known that I, EDWARD W. GILLON, of Brooklyn, county of Kings, and State of New York, have invented an Improvement in Method of Tempering BessemerSteel Vire, of which the following description, in connection with the accompanying drawing, is aspecification, like letters on the drawing representing like parts.

My invention relates to a method of treating and tempering Bessemer or open-hearth steel wire, which consists, first, in hard-drawing the said steel wire, and subjecting the said hard-drawn steel wire to temper heat in a bath of molten metal and then suddenly cooling the same, substantially as will be described.

My improved method of tempering openhearth or Bessemer steel wire is particularly adapted for tempering steel wire in the form of a spring, so that the said spring may possess toughness and at the same time have its elasticity increased to such degree that it will not set or fail to recover its full length or original shape when the compressing or bending force to which it is subjected is removed.

Other features of my invention will be pointed out in the claims at the end .of this specification.

The drawing shows a spiral spring composed of Bessemer or open-hearth steel tempered in accordance with my invention.

In making springs in accordance with my invention the Bessemer or open-hearth steel wire is first hard-drawn and then made or bent into the proper shape by the usual methods, and is then preferably covered with oil, preferably lard-oil, after which the oil-coated wire spring is completely submerged in a bath of molten metal, preferably lead, and the said bath raised to a temperature about 650 Fahrenheit, more or less, the said wire, after being heated for a definite or predetermined time, being then immediately immersed in a bath of oil, water, or other suitable substance. The molten metal prevents the air coming in contact with the spring being heated, thereby enabling the said spring to receive a uniform heat throughout its mass, so that when it is immersed. in the bath of oil, water, or other tempering-fluid the said spring will receive a uniform temper throughout its entire mass.

The predetermined time which the spring is permitted to remain in the bath of molten metal varies with wire of different areas in cross-section; but in most of my experiments I have found from twenty to twenty-five seconds a sufficient time to produce a favorable result.

It has been demonstrated by actual test that springs made of hard-drawn Bessemer or openhearth wire and tempered by this method possess practically permanent elasticity, the said springs receiving practically no set or permanent distortion from their original shape when acted upon by a great compressing force.

Springs such as shown in the drawing have been subjected for a long period of time to a compressing force sufficient to place the coils in contact with one another, the said spring recovering its original size and shape when the compressing force was withdrawn.

Bessemer or open-hearth hard-drawn steel wire treated as above described has imparted to it the desired temper, so that some of the steps employed in the ordinary process of tempering steelsuch as tool-stcel-are omitted, the-said steps consisting in a second heating of the tool-steel and a gradual cooling or letting down of the temper.

1am aware prior to my invention that molten lead has been used to draw the temper of toolsteel, and so I do not claim the use of molten metal for that purpose.

I have herein mentioned the temperature as 650 Fahrenheit, as by that I have obtained excellent results; but I should consider slight variations from said temperature either way within the scope of my invention.

In practice I have found that the tempera ture of the water, oil, Orother tempering fluid should not be over Fahrenheit, the best results being obtained with the temperature between 30 and 40 Fahrenheit.

I claim-- a 1. That improvement in the art or method of treating and tempering Bessemer or openhearth steel wire, which consists in first harddrawing the wire, next bending or twisting it into the form of a spring, then immersing it in oil, then immersing the spring in a bath of molten metal, and finally cooling the spring by suddenly plunging it in a common tempering-bath, substantially as set forth.

2. That improvement in the art or method of making springs, which consists in hardto this specification in the presence of two subdrawing wire of Bessemer or open-hearth steel, scribing witnesses.

properly shaping the spring, and then successively subjecting it to baths 0f 0il,1n0lten metal, EDWARD G 5 at a temperature of about 650 Fahrenheit, Witnesses:

and a cooling-fluid, substantially as set forth. GEORGE F. Ross,

In testimony whereof I have signed my name AUGUSTUS G. MAAS. 

